1. Field of the Invention(s)
The present invention(s) generally relate to processing of data on a transceiver. More particularly, the invention(s) relate to systems and methods for synchronization of clock signals across a backplane of a transceiver.
2. Description of Related Art
In microwave radio systems, a transceiver may include an indoor unit (IDU) and an outdoor unit (ODU) coupled to an antenna. In one example, the IDU may be coupled to a server or other computer over a wired network (e.g., LAN, WAN, or the Internet) or to a mobile network base-station. Information to be wirelessly transmitted may be prepared by both the IDU and the ODU before wireless transmission. Similarly, the outdoor unit may receive signals from the antenna to provide to the server, other computer, or mobile network node via the IDU.
Unlike time-division multiplexing networks, standard Ethernet does not carry clock synchronization information. New standards, such as G8262/Y.1362 from the ITU-T, require a significantly greater precision and accuracy than previous standards. As a result, accurate synchronization of a customer's clock signal across a backplane of a transceiver unit is an increasing challenge. For example, traversing an asynchronous TDM backplane from a digital access card (DAC) to a radio access card (RAC) can cause clock signals to lose precision. Stuffing bits in a nonperiodic, low frequency manner typically adds jitter and/or wander to the clock signal as it traverses a microwave network. The egress clock signal may be used to synchronize a base-station which in turn is used to synchronize mobile devices.